Anna petbonella cbajieb-van deventeb



Reiuued eb. 14,

UNITED STATES ANNA PE'I'BONELLA CRAHER-VAN DEVENTER, F CHESIEBFS, SWITZERLAND PBOCESS IOB PBESEBVIKG 0B- PROTECTING SUBSTANCES OR OBJECTS Io Drawing. Original Io. 1,548,776, dated August 4, 1925, Serial No. 665,475, filed. September 28, 1923.

- Application 101' refisue filed December 14, 1932. Serial No. 647,292.

It is known to preserve food and other substances and also to protect divers articles against contamination by the influence of the atmosphere by covering them with a thin air-excluding film. This method is very suitable for preserving food and the like, in cases where neither heat nor chemical means can be applied, e'. g. when fresh fruits are to be protected from drying or when eggs are to be preserved.

It has been proposed to preserve eggs by applying thereto a solution of rubber, guttapercha or balata, to which may be added wax, ceresine or japan wax. However, to obtain 5 solutions of rubber, organic solvents are necessary, all of which are very viscous in relatively weak solutions. This'is troublesome when applying same. Moreover such organic solvents have a very bad efliect on the smell, and the taste or the condition, or both of most products to be preserved.

The present invention relates to a method of preserving or protecting substance by means of a rubber film which excludes the air, and which avoids the said drawbacks. In some cases it is diificult to obtain a film that really excludes the air, because the usual film-forming substances are injuriously afiected by the very substances which are to' be preserved (e. g. sealing-wax on bottles filled withconcentrated alcohol). According to my invention, an impenetrable coating can be obtained in such cases in a simple way. The invention consists in they use of latex of rubber bearing plants to coat thearticles to be protected by first applying a film of the liquid latex and subsequently causing same to become solid, e. g. by causing it to dry u The whole treatment can take place 40 at or ary temperature. As such coating is an aqueous emulsion, it may be applied even to verydelicate objects, such as fresh fruits. The latex forms a thin coating, which closely conforms to the surface of the articles. This coating hardens into a thin impenetrable film, which wholly covers an object or article or the parts of it to be protected. Thus on the one hand a very resistant coating is obtained, whilst on the other hand heat treatment or an impairing treatment with chemicals, which might have a bad influence on the taste or on other properties, is avoided.

In carrying out the process the following should be taken into account:

(a.) Choice of the lateae.Difierent kinds of latexcan be used for coating, and they can be obtained from different kinds of plants, such as Euphorbiaceae, Moraceae, Sapotaceae, etc. 4 (6.) Preparation of the Zatem..-After be- 1ng obtained from the plant, the latex is passed through a sieve and is kept liquid as tar as possible by means of a preserving agent (e. g. ammonia). The further treatment depends on the nature of the article to be coated. In case the coating is to be applied for instance to the mouth of a corked bottle similarly to sealing wax, no further treatment of the latex is required. When the latex is to be applied as in impenetrable film to food, all substances which emit a smell are first removed from the latex as much as poss1ble. If the film is to be very thin, the latex is diluted beforehand. In other cases a pigment or a fillin material or a disinfectin agent may be a ded.

(0.) Preparation of the article to be 00ated.- '1his is cleaned and brushed with a disinfecting agent if necessary. ((1.) Application of the latest to the arti-' cZe.This is effected by means of a pencilbrush, a glass rod or simply by the finger, or thearticle to be coated may be immersed in the latex in all these cases it is advisable to suspend the article by means of a thread, so that during the treatment the article itself need not be touched.

The coating also may beapplied by first 9o spreading the latex to form a film, causing it to coagulate and then wrapping up the article in the fleece thus obtained. A thin film of liquid latex may be subsequentlyapplied to enclose the article and the loose coat- 05 ing together. f

In case it is diflicult to exclude wholly the air from an article, more than one coating of latex may be applied and other substances,

e. g. pigments, fibresflor other substances to strengthen the film may be included in the coating.

( e.) Hardening of the film.This is at- I tained by causing the latex to dry. The dry latex often remains sticky at first and so adheres to the fingers when newly coated articles are touched. This may be prevented by dusting the coating with talc or by causing the film to harden by chemical means. I (f.) Subsequent sterdlieatioh The articles enclosed in dried latex may be cooked in that state. In most cases a second sterilization is superfluous and with many products, such as fresh fruits, eggs and the like, quite impossible.

9.) Preparation for c0nsumptz'0n.When it is necessary to remove the latex film, e. g. before consuming fruits thus treated, one has only to tear off the fleece by hand; this operation can be facilitated by attaching a thread to the latex.

The advantages of applying an impenetrable coating to articles by means of rubber latex are the following-:

1. It can very easily be applied, no expensive means are required and it may be applied on a small scale. j

2. The coating does not affect the article to be coated, it does not injure the taste nor does it penetrate into the article and it can be applied at ordinary temperature.

3. The coating fortifies the skin of the article, which effect may be increased by including fibres in thelatex.

4. The coating is flexible and so will not chip or crack when the shape of the article is altered (which may be thecase with soft articles).

5. The coating is impenetrable; hence in case the article has a fragile skin; its contents will not be exposed to the influence of the air when the skin is injured (which maybe the case with eggs for instance).

6. The coating is not afi'ected by high temperatures, not even-if these are much higher than the boiling point of water; it is not affected by acids, concentrated alcohol or humidity, nor can it be injured by mold or mildew, bacteria or insects.

7. When once thecoating has hardened,

it can no longer be dissolved by fresh li uid latex, so that a coating when once app ied to an article, cannot be destroyed when the treatment is repeated.

8. If required the coating can easily be removed from the article without leaving any trace on it.

Liquid latex compares favorably with all other coating means because of the favorable properties mentioned especially those mentioned in the clause 2 above, in combination with those mentioned in clauses 6 and 7, and further those mentioned in clauses 4 and 8. Hence, it is especially adapted for coating articles (in order to prevent drying up and contamination) such as, for example, fresh fruit, eggs, cheese and the like, that would neither stand a drastic treatment with disin fecting agents, nor a heat treatment, nor the application of a coating which must be applied in a hot condition or dissolved in organic or corrosive liquids.

Moreover it has been found that corncobs when tl eated with latex are not injured by cornweevils and that cockroaches do not injure photographs which have been coated with latex.

The invention may be applied to many kinds of articles.

What I claim is .1. A process for temporarily preserving or protecting objects comprising the step of applying a temporary preformed air-eit'cfllding fleece-like film of latex to the object under treatment, and then applying a film of liquid latex to said fleece-like film to seal the same around the article.

2. The method of temporarily protecting and preserving articles subject to easy injury, deterioration by exposure, and the like, WhlCh includes coating the article with a film of liquid latex, and allowing the latex to set up into a homogeneous, flexible, readily peelable, temporary coating.

3; The method of temporarily protecting and preserving articles subject to easy injury, deterioration by exposure, and the like, which includes coating the article with a film of liquid latex, allowing the latex to set up into a homogeneous, flexible, readily peelable, temporary coating, and manually tearing ofi the flexible coating to expose the protected articles subject to easy injury, deterioration by exposure, and the like, which includes ap-,

plying a film of latex to completely cover the surface to be protected, allowing the'latex to set up into a homogeneous coating which closely adheres to the protected surface and substantially excludes air from the object coated and then insuring more complete exclusion of air from the object by applying one or more additional coatings'of latex, and allowing said additional coating or coatings to set up into a separate homogeneous film bonded to the first coating, said coating or coatin s of latex forming a flexible and readily pee able temporary coatin which may be manually stripped from the o ject.

6; The met 0d of temporarily protecting and preserving articles subject to easy injur deterioration by exposure, and the like, WlllCh includes coating-the article with a film of liquid latex, in which fibres are included, and allowing the latex to set up into a homogeneous, flexible, readily peelable, temporary coating.

7. The method of temporarily protecting and preserving articles su ject to easy injury, deterioration by exposure, and the like, which includes coating the article with a film of liquid latex,

lowing the latex to set up into a homogeneous,

fiexible, readily peelable, temporary coating, and manually tearing oil the flexible coating to expose the protected surface.

8. The method of preserving or protecting articles subject to easy injur deterioration b exposure, and the like, which includes app ying thereto so asto completely enclose the surface to be protected ahomogeneous coating of liquid latex, in which pigments are ineluded, allowing the latex to set up into a flexible coating which adheres directly to the surfaceprotected, the bond between thelatex deposited coating and the protected surface being such that the latex is easily peelable therefrom without injury to the surface protectcd.

In testimony whereof I afiix my signature.

ANNA PETRONELLA CRAMER-VAN DEVENTER.

in which fibres are included, al- I, 

